1. Field of the Invention
The present invention relates to a pneumatic driving tool, and more particularly to a pneumatic driving tool having a pressure releasing device for suitably releasing the air or the air pressure within the pneumatic driving tool, and for preventing the pneumatic driving tool to continuously drive the fasteners even after the fasteners have been completely or tightly driven onto the objects to be fastened.
2. Description of the Prior Art
Typical pneumatic tool comprise a fan device or a rotor rotatably received within a housing and including a shank extended out of the housing, for engaging with and for driving fasteners or tool extensions or other tool members, and an air inlet for receiving and guiding a pressurized air toward the rotor device, in order to rotate or to drive the rotor device and thus to drive the fasteners or the tool extensions or other tool members.
For example, U.S. Pat. No. 3,827,834 to Kakimoto discloses one of the typical pneumatic tools comprising a van type rotor rotatably received within a motor cylinder, and including a drive shaft extended out of the motor cylinder, for engaging with and for driving fasteners or tool extensions or other tool members. A pressurized air is supplied into the motor cylinder and guided toward the rotor, in order to rotate or to drive the rotor and thus to drive the fasteners by such as the tool extensions or other tool members.
However, when or after the fasteners have been completely or tightly driven onto the objects to be fastened, or after a predetermined driving torque has been applied onto or against the fasteners or the tool extensions or other tool member, the pressurized air may still be or may continuously be supplied into the motor cylinder and may further rotate or to drive the rotor and the fasteners or the tool extensions or other tool member, such that the rotor and the fasteners or the tool extensions or other tool member may be damaged by the typical pneumatic tools.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional pneumatic tool devices.